[dcl.init.ref] Replace normative note with actual note.

Author: tkoeppe

source/declarators.tex

@@ -3304,8 +3304,9 @@
 \pnum
 A reference cannot be changed to refer to another object after initialization.
 \indextext{assignment!reference}%
-Note that initialization of a reference is treated very differently from assignment
-to it.
+\enternote
+Assignment to a reference assigns to the object referred to by the reference (\ref{expr.ass}).
+\exitnote
 \indextext{argument~passing!reference~and}%
 Argument passing (\ref{expr.call})
 \indextext{\idxcode{return}!reference~and}%